Write a MATLAB script file that calculates the sum of first n natural numbers (the program could prompt the user for the number n). The program must use a “for” or “while” loop to accomplish this, and must NOT use the ready formula s = 1 2 n (n + 1).

I NEED THIS QUESTION ANSWER S = 1/2 N(N+1)

Answer 1

[Sara Boznik]

That is easy.

n=input('n:')
sum=0;
for i=1:n
sum=sum+i
end

[Image Analyst]

sum is a built-in function name. Use another name like "theSum" so as to not blow away the built-in function. Also, Harsha is probably not allowed to turn in Sara's solution as his own. And we're not supposed to give full solutions for homework problems so the poster won't get in trouble for cheating.

[Sara Boznik]

yes, I usually use the name in my own language. so I dont have trouble with function name. I used sum in this case that Harsha will understand what the coda means.

Answer 2

[Mohammad Emaz Uddin]

clc;
clear;
close all;

n= input('Enter numbers: ');
sum=0;

for i=1:1:n
    sum=sum+i;
end
disp (sum);

Answer 3

[Tarun Sangwan]

%% using cell method

function b = addds(n)

g = cell(1,n)

for i = 1:n

g{1,i} = i

end

b = sum(g)

%%using recurssion

function v = sums(start,stop,gums)

if start == stop

gums = gums + start

else

gums = gums + start

sums(start+1,stop,gums)

end

v = gums

%%using for loop

for i = 1:n

sum = sum + i

[DGM]

The lack of formatting and line suppression is bad enough, but none of these are valid local functions. You can clearly test that and know that they don't work. Even if you declared the last function and closed all the open scopes, none of these examples work.

The first example is nonsense. The sum() function does not work like that on cell arrays, and even if it did, there would be no point in using a cell array instead of a plain numeric array.

The second example clearly doesn't work because the calls to sums() are simply discarded.

The third example clearly doesn't work because sum() is never declared as a variable. Until it is shadowed, sum() is a function, and calling sum() without any arguments will throw an error.

Why post answers that clearly don't work? This doesn't help anybody.

n = 100;
x = sum(1:n) % reference

x = 5050

b = sum1(n)

b = 5050

v = sum2(1,n,0)

v = 5050

s = sum3(n)

s = 5050

% using cell method
function b = sum1(n)
    g = cell(1,n);
    for k = 1:n
        g{1,k} = k;
    end
    b = sum([g{:}]);
end

% using recurssion
function gums = sum2(start,stop,gums)
    if start == stop
        gums = gums + start;
    else
        gums = gums + start;
        gums = sum2(start+1,stop,gums);
    end
end

% using for loop
function s = sum3(n)
    s = 0;
    for k = 1:n
        s = s + k;
    end
end